Language is a fascinating reflection of culture, and even simple spelling variations can reveal where a word comes from or how it’s used. One common example of this is the difference between customise or customize. You may have seen both spellings in different places and wondered: Which one is correct? The answer depends largely on where you are in the world. Let’s explore the difference between customise or customize, their meanings, usage, and examples.

Meaning of “Customise” or “Customize”

Both customise and customize mean to modify or change something according to a person’s individual requirements or preferences. Whether it’s adjusting a product, a computer setting, or a service, the meaning remains the same — you’re making it personal and unique.

Example meaning:
To customise/customize something is to make it fit your specific needs or taste.

Related: Sundays Or Sunday’s

The Core Difference: British vs. American English

The main difference between customise and customize lies in regional spelling conventions:

• Customise → British English 
• Customize → American English 

This pattern is consistent with other verb pairs such as:

• Realise (UK) vs. Realize (US) 
• Organise (UK) vs. Organize (US) 
• Recognise (UK) vs. Recognize (US) 

So, if you’re writing for a British, Australian, or New Zealand audience, you should use customise. But if your readers are from the United States or Canada, customize is the preferred spelling.

Examples in Sentences

Using “Customise” (British English):

1. The company allows customers to customise their laptop colors and features. 
2. You can customise your meal plan to match your dietary needs. 
3. The teacher asked students to customise their project designs. 

Using “Customize” (American English):

1. Many websites let users customize their profiles and themes. 
2. He decided to customize his car’s interior for a modern look. 
3. The software allows you to customize the settings easily. 

As you can see, the only difference is the spelling — the meaning and function are identical.

Origin and Linguistic Background

The word customise or customize originates from the noun custom, meaning “a traditional practice” or “a habitual way of doing something.”
The suffix -ize (or -ise) is used to form verbs meaning “to make” or “to become.”

• The -ize ending is Greek in origin and was historically used in both British and American English. 
• However, over time, British English adopted -ise endings in many words, even though both are technically correct according to Oxford English standards. 
• American English standardized -ize spellings through Webster’s dictionary reforms in the 19th century. 

Which One Should You Use?

English Type	Correct Form	Example
British English	Customise	You can customise your holiday package.
American English	Customize	You can customize your holiday package.

Tip: Always stay consistent. If you begin writing in American English, stick with customize throughout your text. Similarly, use customise consistently if your writing follows British English conventions.

Common Usage in Technology and Business

In today’s digital world, customise or customize is a popular term across various industries:

• Technology: Customizing software settings, themes, and applications. 
• E-commerce: Customers can customise products like shoes, phones, or gifts. 
• Marketing: Businesses offer customised advertisements and emails. 

For example, “You can customise your dashboard layout” or “Our service lets you customize your experience.”

Regardless of spelling, the focus remains on personalization and flexibility.

Final Thoughts

The difference between customise or customize is purely a matter of regional spelling—not meaning. Use customise in British English. Use customize in American English.

So, whether you write customise or customize, you’re talking about the same concept: making something your own. The choice simply depends on the English variety you follow.